Mark a render function with attributes that will be used by the output — markOutputAttrs
  v1.7.0|Source: 
  
  
    
R/shinywrappers.R
  Description
Mark a render function with attributes that will be used by the output
Arguments
- renderFunc
- A function that is suitable for assigning to a Shiny output slot. 
- snapshotExclude
- If TRUE, exclude the output from test snapshots. 
- snapshotPreprocess
- A function for preprocessing the value before taking a test snapshot.